I want to force the user to enter something into the XrefGroupNum field on the subform before allowing them to enter data anywhere else on the subform. I used the subform's Dirty event to test for null in the XrefGroupNum field. This is fine if the user attempts to enter data in any other field. But, I cannot figure out what to do if the user is trying to enter data in that field as I want them to. In other words (I guess), I can't figure out how to tell if the XrefGroupNum field has the focus when the subform is Dirty.